You can't inactivate the position with the code XXXXXX as an incumbent exists currently or future

Summary:

We are trying to inactivate the position by adding it as the "Funded by" on another position but every time we do that we are getting an error as : You can't inactivate the position with the code XXXXXX as an incumbent exists currently or future,

Any suggestions, solutions or workarounds would be appreciated

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):